Vibration damping materials have been generally used to absorb vibration energy in the places where vibration occurs such as vehicles, railway cars, aircraft, household appliances, office automation equipment, precision apparatuses, building equipment, civil engineering equipment, shoes, sports goods.
Patent Document 1, for example, discloses a polyester resin composition having a partial structure in which the number of carbon atoms between the ester linkages of the main chain is an odd number, as a damping material to absorb the vibration energy. This polyester resin composition is excellent in the damping performance around room temperature and promising as a damping material. However, when carbon or mica powders and the like, which are electroconductive materials, are dispersed in the polyester resin, it is difficult to produce the damping material with the thickness less than 200 μm and it cannot be used as a damping material for film application.
Rubber materials such as butyl rubber and nitrile rubber (NBR), which are excellent in processability, mechanical strength and material cost, are also being used as a vibration damping material in a wide range. However, although these rubber materials have the best damping property (performance to insulate or relax the transmission of vibration energy) among common polymeric materials, the damping property (property to absorb vibration energy) of the rubber materials is not sufficient to use them alone. Therefore, the rubber materials cannot exhibit sufficient damping property when used as the damping material for, for example, film application.